1. Field of the Invention
The present invention relates a new spray device for the fine spray dispersion of, e.g., liquids such as water including mineral or thermal spring water, comprising a propellent gas mixture.
2. Discussion of the Background
The beneficial physiological and therapeutic properties of mineralized waters, such as mineral and thermal spring waters, have been known for quite some time. Mineralized waters contain beneficial mineral salts and trace elements. Application of mineralized waters as a fine mist to the skin provides the skin with an even distribution of the beneficial mineral salts and trace elements of mineralized waters. In addition, such an application provides an overall feeling of freshness.
Portable personal aerosol containers were developed so that the public could take advantage of the beneficial properties of various waters. For example, as described in F. Clanet, Presse thermale et climatique, 1986, 123, No. 1,: xe2x80x9cLe conditionnement des eaux sulfurxc3xa9es en emballages axc3xa9rosols permettant leur utilisation individuellexe2x80x9d [translation: xe2x80x9cThe packaging of sulphur waters in aerosol containers would permit their personal usexe2x80x9d].
The use of a gag for pressurizing an aerosol container, is well known in the art.
Nitrogen is one gas commonly used to pressurize aerosal containers. However, the pressure of nitrogen gas can cause water soluble ions of high ion content mineralized waters, in particular waters having a high concentration of carbonate or bicarbonate ions, to precipitate. As a result, the chemical composition of the mineralized water is modified which, in turn, can modify the waters"" properties and ultimately, the waters"" effect on the skin. Furthermore, the ion precipitation increases the risk of blockage of the exit nozzle of the aerosol container which would render the aerosol container inoperable.
Special Medicinal Patent No. 3574 describes the use of carbon dioxide gas in aerosol containers equipped with mechanical propulsion systems. However, when carbon dioxide is used in an aerosol container unequipped with a mechanical propulsion system, several problems result. Instead of a fine spray, which is defined as a cloud of particles having a size of between 50 xcexcm and 120 xcexcm, the aerosol container produces water droplets or a liquid jet. Also, liquid leaks form at the atomizer passage of the aerosol container. A spray device that produces such problems is not suitable for marketing.
Also well known in the art is the need to decontaminate the aerosol container once the aerosol container has been pressurized and filled with gas and mineralized water to prevent microbial growth in the water. Decontamination is usually achieved by physical methods, such as heat or ionizing treatments. However, such decontamination methods are very expensive.
Therefore a need still exists for a portable personal aerosol container or spray device which overcomes such problems as ion precipitation, poor spray dispersion and leakage. Furthermore, an alternate and less-expensive decontamination process for a spray device is also needed.
Applicants have surprisingly discovered that a personal aerosol or spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide overcomes these problems and, in addition, provides a liquid, such as water, that is better tolerated by the skin.
Accordingly, one object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide.
Another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of a liquid or atomizable composition.
Another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of a liquid or atomizable composition, such as mineralized water, which overcomes the problems associated with previous aerosol containers such as ion precipitates and liquid jet.
Another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of mineralized water which not only reduces the bacteria content of the mineralized water contained in the spray device, but can also maintain very low levels of bacteria in the water for a lengthy period of time without needing to undergo a physical decontamination process.
Still another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of mineralized water wherein the gas mixture adjusts the pH of the contained mineralized water close to that of the skin.
Still another object of the present invention is to provide a spray device pressurized by a gas mixture comprising nitrogen and carbon dioxide for the application of a liquid or atomizable composition, such as mineralized water, wherein the liquid or atomizable composition can further comprise cosmetic and/or dermatological adjuvants.
The spray device of the present invention comprises a container, a propellent gas mixture, a valve and a means for atomizing.
The spray device of the present invention can be used in the application of a liquid or atomizable composition, preferably, of mineralized waters, more preferably, mineral or thermal spring waters. These waters can contain, inter alia, trace elements such as iron (Fe), manganese (Mn), copper (Cu), aluminum (Al) and arsenic (As), and dissolved minerals such as carbonate, bicarbonate (HCO3xe2x88x92), sulfates (SO42xe2x88x92), thiosulfates (S2O32xe2x88x92), hydrogensulfide (HSxe2x88x92), sodium (Na+), potassium (K+), lithium (Li+), calcium (Ca2+), magnesium (Mg2+) and strontium (Sr2+). It is known that these waters, depending upon the particular mineral and trace element content, can be used for therapeutic purposes such as moisturizing and desensitization of the skin or the treatment of certain dermatoses.
The mineral or thermal spring waters are, preferably, naturally occurring mineral or thermal spring waters or naturally occurring mineral or thermal spring waters enriched with additional dissolvable minerals and/or trace elements or enriched with aqueous solutions prepared from purified water (demineralized or distilled water) enriched with dissolvable minerals and/or trace elements.
Naturally occurring thermal spring or mineral waters for use in the spray device of the present invention are, preferably, water from Vittel, water from the Vichy basin, water from Uriage, water from La Roche Posay, water from La Bourboule, water from Enghien-les-Bains, water from Saint Gervais-les-Bains, water from Nxc3xa9ris-les-Bains, water from Allevar-les-Bains, water from Digne, water from Maizixc3xa8res, water from Neyrac-les-Bains, water from Lons-le-Saunier, water from Eaux-Bonnes, water from Rochefort, water from Saint Christau, water from Les Fumades, water from Tercis-les-Bains or water from Avene.
The mineral or thermal spring waters for use in the spray device of the present invention can also be those with relatively high concentration of carbonates or bicarbonates such that precipitate formation is not observed. Mineral or thermal spring waters such as water from Vittel, water from the Vichy basin, water from Uriage, water from La Roche Posay, water from La Bourboule, water from Enghien-les-Bains or water from Les Fumades, contain a total concentration of carbonates or bicarbonates of greater than 360 mg/L, and, upon use, do not exhibit precipitate formation and the disadvantages associated therewith.
The liquid or atomizable composition, preferably mineralized water, contained in the spray device of the present invention can further contain cosmetic and/or dermatological adjuvants such as preservatives, antioxidants, fragrances, UV-screening agents, coloring materials, and hydrophilic or lipophilic active principles. The adjuvants should not effect the integrity of the liquid or atomizable composition, preferably mineralized water, or produce negative side effects once the liquid or atomizable composition, preferably mineralized water, is sprayed onto the skin. The adjuvants are preferably those that can be distributed in the form of a spray or can be atomized. In addition, the adjuvants are preferably those which do not interfere with the working of the spray device, in particular those that do not block the atomizer passage.
Coloring materials or colorants used in the present invention are those well known to those skilled in the art. The colorants can be inorganic or organic colorants or dyestuffs.
Fragrances for use in the present invention are those well-known to one skilled in the art. The fragrances can be natural or synthetic.
The hydrophilic or lipophilic active principles, which are preferably hydrophilic so that they can be dissolved in an aqueous lotion based on mineral water, can treat the skin and can be anti-aging active principles, anti-wrinkle active principles, moisturizers or humectants, depigmenting active principles, active principles for combating free radicals (radical oxygen species), nutritive active principles, protective active principles, restructuring active principles, toning active principles, anti-acne active principles, exfoliating active principles, emollient active principles. The active principles can also treat skin diseases, such as mycones, dermatitides, psoriasis and the like.
Anti-acne, anti-aging, anti-wrinkle, moisturizing or exfoliating active principles are those well-known to one skilled in the art and can, preferably, be xcex1-hydroxy acids such as glycolic, lactic, malic and citric acids and the like.
The active principles are added to the liquid or atomizable composition, preferably, mineralized water in proportions appropriate for its intended purpose. Preferably, 0.01% to 10% by weight of the active principle with respect to the total weight of the composition is added. More preferably, 0.05-5% by weight, more preferably still, 0.1-1% by weight, and even more preferably 0.15-0.5% by weight of the adjuvant is added.
The propellent gas mixture employed in the spray device of the present invention is a mixture comprising nitrogen (N2) and carbon dioxide (CO2). Preferably, the propellent gas mixture consists essentially of N2 and CO2.
Spray tests were conducted with spray devices pressurized by propellent gas mixtures comprising variable percentages by volume of nitrogen and carbon dioxide. The tests indicated that in order to prevent the formation of liquid jet at the end of spraying, the propellent gas mixture, preferably, contained greater than 30% by volume of nitrogen of the total gas volume.
The tests also indicated that in order to prevent the formation of ion precipitates or, when the spray device contains mineralized water, mineral salt precipitates or deposits, the propellent gas mixture preferably contained at least 40% by volume of carbon dioxide of the total gas volume.
The percentage by volume of nitrogen and carbon dioxide of the total gas volume of the propellent gas mixture, preferably, satisfies the relationship (Rel. I):
40/60 less than %N2/%CO2 less than 60/40
and
%N2+%CO2=100xe2x80x83xe2x80x83(Rel. I)
More preferably, the percentage by volume of each gas of the total gas volume satisfies the following relationship (Rel. II):
%N2=%CO2=50xe2x80x83xe2x80x83(Rel. II)
but the propellent gas mixture may be composed of 40, 45, 50, 55 or 60% by volume nitrogen with carbon dioxide making up the remainder percentage up to 100%.
The use of carbon dioxide in the propellent gas mixture of the spray device of the present invention can also effect the pH of the liquid or atomizable composition, especially mineral or thermal spring waters, contained in the spray device of the present invention. According to the state of the art, when nitrogen alone is used as the propellent gas, the pH of the contained water at the outlet of the device is between 7 and 8 or neutral to slightly basic. The presence of CO2 in the propellent gas mixture allows CO2 to become dissolved in the contained water and as a result, the pH of the water is lowered or acidified such that the pH is closer to that of the skin, which is between 5 and 6. The pH of the water is usually between 6.0 and 6.9, and, preferably between 6.5 and 6.7. As a result, such water is better tolerated by the skin, especially by sensitive to very sensitive skin.
Furthermore, although carbon dioxide is known for its bacteriostatic properties (xe2x80x9cThe Inhibition by CO2 of the Growth and Metabolism of Microorganismsxe2x80x9d, N. M. Dixon, Journal of Applied Bacteriology, 1989, 67, 109-136), a propellent gas mixture of nitrogen and carbon dioxide used in the spray device of the present invention, preferably wherein the nitrogen and carbon dioxide ratio satisfies Rel. I and, more preferably still, satisfies Rel. II, was not expected to reduce the number of germs present in the medium to be sprayed. By having CO2 as a component of the propellent gas mixture, it is possible to obtain a medium of mineral and/or thermal spring water with low levels of contamination of less than or equal to 10 germs per 100 ml and, preferably, of less than or equal to 1 germ per 100 ml, in a few days (methods for counting germs followed as given in the European Pharmacopoeia, 2nd Edition, 1983, Vol. I, V.2.1.8) without having to resort to physical decontamination methods.
Different types of means for atomizing or atomizer passages have been tested to optimize the quality of the spray dispersion of a spray device of the present invention as a fine mist. Preferably, an atomizer passage with a nozzle equipped with three vortical channels is used. By using this type of atomizer passage, a propellent gas mixture having a high percentage by volume of carbon dioxide, up to 70% of CO2, can be used in the spray device of the present invention to produce of fine spray or mist without the formation of liquid jet at the end spraying.
The valve of the spray device of the present invention provides a satisfactory feed of the contained medium to the atomizer passage without the risk of blockage. Preferably, a valve which can be used head upwards and head downwards is chosen, in order to avoid loss of propellent gas mixture in the event of improper use of the spray canister. More preferably, a valve which can be used exclusively head upwards is envisaged.